Method for loading and transporting coal

ABSTRACT

Coal is transported in a vehicle compartment which has a firesupressing atmosphere of carbon dioxide recovered from the exhaust fumes produced by the vehicle-propelling engine.

United States Patent 1 91 Wartes Dec. 24, 1974 METHOD FOR LOADING AND 2,756,215 7/1956 Burgess et al 169/12 x TRANSPORTING COAL 2,961,050 11/1960 MacCracken.... 169/12 3,103,296 9/]963 Gour 169/12 X Inventor: Lloyd Wartes, 550 12th 3,389,972 6/1968 POIIhalSl,Jr. 169/12 x Suite 1905, Denver, Colo. 80203 3,438,445 4/1969 MacCracken 169/12 X [22] Flled: 1972 Primary ExaminerLloyd L. King [21] Appl. No.: 300,032 Assistant ExaminerMichael Mar 7 Attorney, Agent, or FirmBrowne, Beveridge, 52 US. Cl 169/45, 169/11, 169/62 DeGrand18 [51] Int. Cl. A62c l/14 58 Field 61 Search 169/1 A, 2 R, 2 A, 11, [571 ABSTRACT 169/12, 43, 45, 46, 62; 214/38 Coal is transported in a vehicle compartment whic has a fire-supressing atmosphere of carbon dioxide rep [56] References Cited covered from the exhaust fumes produced by the vehi- UNITED STATES PATENTS cle-propelling engine- 2,450,537 10/1948 Williamson 169 12 X 4 Claims, 1 Drawing Figure PAIEm naEczmu fi s @225 lllllllil METHOD FOR LOADING AND TRANSPORTING COAL This invention relates to a method for transporting coal in a safe and economical manner.

Normally, coal is transported on railraod cars in its natural state wherein it has a relatively high density due to the substantial water content of the coal. It has previously been suggested that the coal be dehydrated by well-known processes prior to shipment in order to reduce its weight, but these proposals have not been practical due to the extremely high flammability and low ignition temperature of dehydrated coal.

The present invention permits the transportation of dehydrated coal without any substantial risk of fire, since the coal is carried in a transport vehicle, preferably a railroad train, in an atmosphere of carbon dioxide which has been recovered from the propelling engine of the vehicle. Engine exhausts have previously been fed directly to cargo-containing compartments for the purpose of fire suppression.

In addition to the economy of shipment according to this proposal, there is the advantage of reducing the amount of pollutants introduced into the air by the propelling engine, since the exhaust gases are processed for removal of carbon dioxide before being released to the atmosphere.

Preferably, this invention is performed by providing a railroad train with means for processing its diesel exhaust gases to recover the carbon dioxide therefrom. The carbon dioxide'is stored under pressure and released into the individual coal compartments as coal is being loaded therein, serving to supress fires both by providing a protective atmosphere and by its coolant effect which reduces the temperature of the coal to below its ignition temperatures. The compartments are sealed so the coal remains in the fire-suppressing protective atmosphere throughout its shipment. The coal, being in a dehydrated condition, is quite light and will permit the use of longer trains and reduce shipping costs. It is anticipated that the invention will be practiced with unit trains specially designed for this purpose.

Those skilled in the chemical arts will recognize that there are many ways of processing exhaust gases to remove carbon dioxide. lt is known that the diesel engine exhaust is composed primarily of carbon dioxide, nitrogen in its diatomic state and water, with minor amounts and carbon monoxide then passes into a tank 10 which is connected to the inlet of another compressor 12 which has a series of compression and cooling stages which raise its pressure to at least about 35 atmospheres and a temperature of 0C. Under these conditions, carbon dioxide will be in its liquid state. The nitrogen and any residual carbon monoxide remain in their gaseous state and may be released to the atmosphere as exhaust, leaving only liquid carbon dioxide in the system. This liquid carbon dioxide is then maintained under pressure in a refrigerated tank 14 which has its outlet connected to manifold carbon dioxide distributors 16 in each coal compartment. As previously explained, the carbon dioxide is released into the dehydrated coal as the car is being loaded, to reduce the temperature of the coal and to surround it in a firesupressing atmosphere. The car is made as air tight as possible by using gasketed covers and discharge gates. Additional carbon dioxide is introduced into the compartment as necessary in transit to reduce air infiltration and to ensure that ignition and combustion of the coal cannot occur.

It will be appreciated that many different approaches may be used to practice the invention. Different systems may be used for recovering the carbon dioxide from the exhaust fumes. The volume of carbon dioxide kept in the refrigerated storage tank may be supplemented by carbon dioxide recovered from the exhaust fumes of other diesel engines. The invention may also be used for certain types of non-dehydrated coal which presently cannot be shipped due to their extreme flammability.

The nature of the apparatus required to recover carbon dioxide from the exhaust fumes is such that the invention presently appears practical only for use with railroad or marine coal transporting facilities, preferably unittrains specifically constructed for this purpose. However, if carbon dioxide'recovery systems become available on a scale suitable for use on highway vehicles, the exhaust gases of a tractor-trailer may be processed to recover carbon dioxide for use in providing a fire-suppressing atmosphere for a cargo of coal in such a vehicle. Other suitable environments for the invention and other methods of carrying it out may readily be developed, so it is emphasized that the invention is not limited only to the described embodiment, but also encompasses equivalents thereof within the spirit of the claims which follow.

I claim:

l. A method of transporting coal including the steps of injecting liquid carbon dioxide into the coal while loading the coal into a coal compartment to reduce the temperature of the coal to below its ignition temperature and to surround it in a fire-suppressing atmosphere, providing said coal compartment with a protective atmosphere containing sufficient carbon dioxide to prevent ignition and combustion of the coal, propelling the coal in the protective atmosphere with an engine which produces exhaust fumes, processing the exhaust fumes by compression and cooling them to liquefy and recover the carbon dioxide therefrom, storing the carbon dioxide, and utilizing the carbon dioxide recovered from the engine exhaust for said injecting step and for providing the protective atmosphere.

2. The method according to claim 1 wherein the haust fumes are diesel exhaust fumes.

3. The method according to claim 1 including the step of releasing nitrogen and carbon monoxide in the vapor state from the carbon dioxide liquefied by the compression and cooling steps.

4. The method according to claim 1 wherein the coal is dehydrated prior to the loading step. 

1. A method of transporting coal including the steps of injecting liquid carbon dioxide into the coal while loading the coal into a coal compartment to reduce the temperature of the coal to below its ignition temperature and to surround it in a fire-suppressing atmosphere, providing said coal compartment with a protective atmosphere containing sufficient carbon dioxide to prevent ignition and combustion of the coal, propelling the coal in the protective atmosphere with an engine which produces exhaust fumes, processing the exhaust fumes by compression and cooling them to liquefy and recover the carbon dioxide therefrom, storing the carbon dioxide, and utilizing the carbon dioxide recovered from the engine exhaust for said injecting step and for providing the protective atmosphere.
 2. The method according to claim 1 wherein the exhaust fumes are diesel exhaust fumes.
 3. The method according to claim 1 including the step of releasing nitrogen and carbon monoxide in the vapor state from the carbon dioxide liquefied by the compression and cooling steps.
 4. The method according to claim 1 wherein the coal is dehydrated prior to the loading step. 